Multi-layer ceramic composite porous structure

ABSTRACT

An article of manufacture includes a first ceramic matrix composite (CMC) sheet having a number of flow passages therethrough, and a CMC foam layer bonded to the first CMC sheet. The CMC foam layer is an open-cell foam. The article of manufacture includes a second CMC sheet bonded to the CMC foam layer, the second CMC sheet having a thermal and environmental barrier coating and having a number of flow passages therethrough.

RELATED APPLICATIONS

This application is a divisional of application Ser. No. 13/337,106,filed Dec. 24, 2011, which claims the benefit of United StatesProvisional Patent Application No. 61/428,701, filed Dec. 30, 2010,which is incorporated herein by reference.

BACKGROUND

The technical field generally relates to high-temperature, light-weightmaterials. Ceramic matrix composite materials in the presently known arthave limitations in the structural capabilities and the cooling methodsavailable. Presently available ceramic components are cooled by directflow or impingement cooling. Further, presently available metalmaterials require high cooling loads to achieve sufficient cooling inhigh-temperature applications, requiring low temperature cooling fluidsand/or high cooling fluid flow rates. Therefore, further technologicaldevelopments are desirable in this area.

SUMMARY

One embodiment is a unique article of manufacture including a ceramicmatrix composite, a ceramic matrix composite foam layer and anotherceramic matrix composite bonded thereto. Other embodiments includeunique methods, systems, and apparatus to related to the article ofmanufacture and method of manufacture. Further embodiments, forms,objects, features, advantages, aspects, and benefits shall becomeapparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a schematic diagram of a multi-layer porous compositestructure.

FIG. 1b is an exploded view of a multi-layer porous composite structure.

FIG. 2 is a schematic diagram of a multi-layer porous compositestructure having a woven layer.

FIG. 3 is a schematic diagram of a component formed from a multi-layerporous composite structure.

FIG. 4 is schematic diagram of another multi-layer porous compositestructure.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, any alterations and further modificationsin the illustrated embodiments, and any further applications of theprinciples of the invention as illustrated therein as would normallyoccur to one skilled in the art to which the invention relates arecontemplated herein.

Referencing FIG. 1, an article of manufacture 100 is illustrated havinga first ceramic matrix composite (CMC) sheet 102. In certainembodiments, the CMC sheet may be woven (e.g. reference FIG. 2),braided, or formed by standard processing. The article 100 includes flowpassages 104 through the first CMC sheet 102, and a CMC foam layer 106bonded to the first CMC sheet 102. The CMC foam layer 106 is anopen-cell foam, allowing fluid flow through the bulk of the CMC foamlayer 106. The article of manufacture 100 further includes a second CMCsheet 108 bonded to the CMC foam layer 106. The flow permeabilitythrough the foam and the structural contribution of the foam layer tothe article 100 are selectable according to the foam cell sizing anddensity.

An exemplary embodiment includes forming and rigidizing the first CMCsheet 102 before application and bonding of the CMC foam sheet 106, thenapplying the second CMC sheet 108. In certain embodiments, article 100further includes flow passages 110 (reference FIG. 1b ) through thesecond CMC sheet 108. The article 100 may be processed to completion(e.g. rigidizing and de-greening the article) after the application ofthe second CMC sheet 108, or the second CMC sheet 108 may be rigidizedbefore the application of further layers. An exemplary article ofmanufacture 400 (reference FIG. 4) includes additional CMC foam layer(s)402, each additional CMC foam layer 402 bonded to and alternated with aCMC sheet (108, 404). Each of the CMC sheets (102, 108, 404) may beperforated (drilled, punched, etc.) after rigidizing. In certainembodiments, one or more of the sheets 102, 108, 404 do not include flowpassages therethrough. In certain embodiments, the flow passages throughthe sheets 102, 108, 404 are inherent to the sheet construction—forexample where the sheets 102, 108, 404 have a braided or wovenconstruction having gas permeable gaps.

Returning to FIG. 1 a, in certain embodiments, the perforations 104, 110may be staggered or aligned to facilitate the desired flow permeabilitythrough the article 100. For example, the perforations 104, 110 may bein any degree of alignment between direct alignment and maximum possibleaverage offset. The flow permeability through the article 100 is furtherselectable with the sizing and count of the perforations 104, 110. Thus,a configurable flow permeability is provided through the article 100, orfrom the interior of the article 100 through one or both of the sheets102, 108.

The article of manufacture 100 may be a component including a cooled gasturbine engine combustion chamber liner, a non-cooled gas turbine enginecombustion chamber liner, a cooled gas turbine engine exhaust liner, anon-cooled gas turbine engine exhaust liner, a cooled rotating blade fora gas turbine, a non-cooled rotating blade for a gas turbine, a cooledvane for a gas turbine, and/or a non-cooled vane for a gas turbine. Incertain embodiments, the second CMC sheet 108 includes a thermal andenvironmental barrier coating. Any of the CMC sheets 102, 108, 404, andespecially any CMC sheets exposed to a heated and/or corrosiveenvironment, may include a thermal and/or environmental barrier coating.

Referencing FIG. 3, schematic diagram of a component 300 formed from amulti-layer porous composite structure is illustrated. The exemplarycomponent 300 is a compressor blade, a turbine blade, or a stator vane.The component includes a first CMC sheet 102, a second CMC sheet 108,and an open-cell CMC foam layer 106. The component 300 is mechanicallycoupled to a base 308 (e.g. a compressor hub), the base 308 including acoolant passage 306 that flows coolant into the component 300. Theexemplary component 300 includes flow passages 104 in only one of theCMC sheets, where the coolant flow 302 enters the gases passing by thecomponent 300. A component 300 may include flow passages 104 in eitherof the sheets 102, 108, and/or both of the sheets 102, 108. In certainembodiments, the component 300 is a ceramic composite component thatwithstands high temperatures and has some internal cooling capabilityfrom the coolant flow 302 therethrough. The heat transfer value from thecomponent 300 to the coolant flow 302 may be provided at a lower valuethan a heat transfer value that would be required for a metalliccomponent to avoid failure. Accordingly, adjustments to the size of thecoolant passage 306, the coolant flow rate, the coolant temperature,and/or other modification of the coolant flow environment through thecomponent 300 may be made to lower costs and/or improve reliability ofthe component 300 relative to a metallic component performing a similarstructural function. Exemplary, non-limiting adjustments include:providing a smaller coolant passage 306, providing a lower coolant flowrate, and providing a higher coolant temperature.

The procedural descriptions which follow provide an illustrativeembodiment of performing procedures for providing a multi-layer ceramiccomposite porous structure. Operations illustrated are understood to beexemplary only, and operations may be combined or divided, and added orremoved, as well as re-ordered in whole or part, unless statedexplicitly to the contrary herein. Certain operations illustrated may beimplemented by a computer executing a computer program product on acomputer readable medium, where the computer program product comprisesinstructions causing the computer to execute one or more of theoperations, or to issue commands to other devices to execute one or moreof the operations.

An exemplary procedure includes an operation to provide a multi-layerceramic matrix composite (CMC) component having two opposing CMC sheetsand a CMC open-cell foam layer therebetween. The procedure furtherincludes an operation to expose one of the CMC sheets directly tohigh-temperature turbine engine gases. The exemplary procedure furtherincludes an operation to flow a coolant fluid through the CMC open-cellfoam layer and through at least one of the CMC sheets. In certainembodiments, the procedure further includes exposing the CMC sheetdirectly to high-temperature turbine engine gases by flowing turbineengine combustion gases in contact with the CMC sheet. Exemplaryembodiments include rotating the multi-layer CMC component during theexposing, for example where the multi-layer CMC component is a rotatingblade including a combustion gas turbine blade mechanically coupled toan upstream compressor blade.

In certain embodiments, the procedure includes providing a first heattransfer value from the multi-layer CMC component to the coolant fluidthat is lower than a second heat transfer value. The second heattransfer value is a required heat transfer for a metal component. Theheat transfer values comprise an amount of heat removed from thecomponent per unit of time relative to a given exhaust temperature andflow rate. In certain embodiments, the heat transfer value is relatableto an operating temperature of the component, where the second heattransfer value is lowered thereby providing a higher operatingtemperature for the multi-layer CMC component than would be required fora metal component performing an identical structural task. The metalcomponent may be a superalloy, steel, titanium, aluminum, or other metalcomponent that could be configured to provide a mechanically similarfunction in a similar application.

Another exemplary procedure includes an operation to form a firstceramic matrix composite (CMC) sheet, and an operation to provide anumber of flow paths therethrough (e.g. by perforating the first CMCsheet or by forming the CMC sheet with inherent gas permeablepassageways). The procedure further includes an operation to rigidizethe first CMC sheet into a component shape. In certain embodiments, therigidizing is performed before the providing the flow paths.

The procedure further includes an operation to bond a shaped, open-cellCMC foam layer to the first CMC sheet, where the shaped, open-cell CMCfoam layer has a shape corresponding to the component shape. Forexample, the component may be an airfoil vane utilized in a turbineengine, and the first CMC sheet and CMC foam layer form one face and aninterior of the airfoil vane. The exemplary procedure further includesan operation to form a second CMC sheet, and an operation to bond thesecond CMC sheet to the foam layer thereby forming a componentstructure. The procedure further includes an operation to cure thecomponent structure. In certain embodiments, the procedure includes anoperation to provide a number of flow paths through the second CMC sheetbefore the operation to bond the second CMC sheet. In certainembodiments, the procedure includes an operation to apply a thermal andenvironmental barrier coating to the second CMC sheet.

In certain embodiments, the exemplary procedure further includes, beforethe curing the component structure, an operation to rigidize the secondCMC sheet, to bond a second shaped, open-cell CMC foam layer to thesecond CMC sheet, to form a third CMC sheet, and to bond the third CMCsheet to the second foam layer thereby enlarging the componentstructure. Certain embodiments of the procedure include operations toadd open-cell CMC foam layers and additional CMC sheet layers to buildthe component to a specified configuration.

An exemplary embodiment of the procedure includes an operation todetermine a component strength requirement, and in response to thecomponent strength requirement, to determine at least one designparameter. The design parameter includes a number of layers each layercomprising a CMC foam layer interposed between two CMC sheets, athickness of each of the CMC sheets, a density of the CMC foam layer,and/or a geometric shape of the component structure. The procedurefurther includes conforming the component structure to the designparameter(s).

Another exemplary embodiment of the procedure includes an operation todetermine a component cooling capability requirement, and in response tothe component cooling capability requirement, to determine at least onedesign parameter. The design parameter includes a sizing of the flowpaths, a shape factor of the flow paths, an alignment value of the flowpaths, a thermal and environmental barrier coating design, and/or adensity of the CMC foam layer.

An exemplary shape factor includes a contribution of the pressure dropof flow through the component that results from the geometrical aspectsof the component, including the component thickness, overall shape, thenumber of flow paths provided in the CMC sheets and CMC foam layer, andother geometrical aspects understood in the art. An exemplary alignmentvalue of the flow paths includes a degree to which an average flow pathprovided in a first CMC sheet aligns or is displaced from an averageflow path provided in a second CMC sheet. The procedure further includesan operation to conform the component structure to the design parameter.

As is evident from the figures and text presented above, a variety ofembodiments according to the present invention are contemplated.

An exemplary embodiment is an article of manufacture, including a firstceramic matrix composite (CMC) sheet having flow passages therethroughand a CMC foam layer bonded to the first CMC sheet, where the CMC foamlayer is an open-cell foam. The article of manufacture further includesa second CMC sheet bonded to the CMC foam layer. Certain embodiments ofthe article of manufacture include a number of flow passages through thesecond CMC sheet, and the perforations may be staggered or aligned tofacilitate the desired flow permeability through the article ofmanufacture, or through the relevant portion of the article ofmanufacture. The flow passages may be perforations in the first and/orsecond CMC sheets. In certain embodiments, the flow passages are gaspermeable gaps in the CMC sheets formed by woven and/or braided CMCsheets. The article of manufacture may include additional CMC foamlayers, with each CMC foam layer bonded with and alternated with a CMCsheet.

In certain embodiments, the article of manufacture further includesadditional CMC foam layers, where each of the additional CMC foam layersis bonded to and alternated with an additional CMC sheet. The article ofmanufacture may be a component including a cooled gas turbine enginecombustion chamber liner, a non-cooled gas turbine engine combustionchamber liner, a cooled gas turbine engine exhaust liner, a non-cooledgas turbine engine exhaust liner, a cooled rotating blade for a gasturbine, a non-cooled rotating blade for a gas turbine, a cooled vanefor a gas turbine, and a non-cooled vane for a gas turbine. In certainembodiments, the second CMC sheet includes a thermal and environmentalbarrier coating. Any of the CMC sheets, and especially any exposed CMCsheets to a heated and/or corrosive environment, may include a thermaland/or environmental barrier coating.

Another exemplary embodiment is a method, including providing amulti-layer ceramic matrix composite (CMC) component having two opposingCMC sheets and a CMC open-cell foam layer therebetween. The methodincludes exposing one of the CMC sheets directly to high-temperatureturbine engine gases, and flowing a coolant fluid through the CMCopen-cell foam layer and also through at least one of the CMC sheets.The exemplary method further includes exposing the CMC sheet directly tohigh-temperature turbine engine gases by flowing turbine enginecombustion gases in contact with the CMC sheet. The method may furtherinclude rotating the multi-layer CMC component during the exposing, forexample where the multi-layer CMC component is a rotating bladeincluding a combustion gas turbine blade mechanically coupled to anupstream compressor blade. In certain embodiments, the method furtherincludes providing a first heat transfer value from the multi-layer CMCcomponent to the coolant fluid that is lower than a second heat transfervalue, where the second heat transfer value is a required heat transferfor a metal component. The metal component may be a superalloy, steel,titanium, aluminum, or other metal component that could be configured toprovide a mechanically similar function in a similar application.

Yet another exemplary embodiment is a method including forming a firstceramic matrix composite (CMC) sheet, and providing a number of flowpaths therethrough. The method further includes rigidizing the first CMCsheet into a component shape and bonding a shaped, open-cell CMC foamlayer to the first CMC sheet, where the shaped, open-cell CMC foam layerhas a shape corresponding to the component shape. The method furtherincludes forming a second CMC sheet, and bonding the second CMC sheet tothe foam layer thereby forming a component structure. The method furtherincludes curing the component structure. In certain embodiments, themethod includes providing a number of flow paths through the second CMCsheet before the bonding the second CMC sheet. The flow paths may beprovided by perforating the first CMC sheet and/or the second CMC sheet.In certain embodiments, the method includes applying a thermal andenvironmental barrier coating to the second CMC sheet before theperforating. The perforations for the first CMC sheet and the second CMCsheet may be staggered.

In certain embodiments, the method further includes, before the curingthe component structure: rigidizing the second CMC sheet, bonding asecond shaped, open-cell CMC foam layer to the second CMC sheet, forminga third CMC sheet, and bonding the third CMC sheet to the second foamlayer thereby enlarging the component structure. Certain embodiments ofthe method include determining a component strength requirement, and inresponse to the component strength requirement, determining at least onedesign parameter including: a number of layers each layer comprising aCMC foam layer interposed between two CMC sheets, a thickness of each ofthe CMC sheets, a density of the CMC foam layer, and/or a geometricshape of the component structure. The method further includes conformingthe component structure to the design parameter(s). The method furtherincludes, in certain embodiments, determining a component coolingcapability requirement, and in response to the component coolingcapability requirement, determining at least one design parameterincluding: a sizing of the flow paths, a shape factor of the flow paths,an alignment value of the flow paths, a thermal and environmentalbarrier coating design, and/or a density of the CMC foam layer. Themethod further includes conforming the component structure to the designparameter(s).

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly certain exemplary embodiments have been shown and described andthat all changes and modifications that come within the spirit of theinventions are desired to be protected. In reading the claims, it isintended that when words such as “a,” “an,” at least one,” or at leastone portion” are used there is no intention to limit the claim to onlyone item unless specifically stated to the contrary in the claim. Whenthe language at least a portion” and/or “a portion” is used the item caninclude a portion and/or the entire item unless specifically stated tothe contrary.

What is claimed is:
 1. A method, comprising: forming a first ceramic matrix composite (CMC) sheet, and providing a plurality of flow paths therethrough; rigidizing the first CMC sheet into a component shape; bonding a shaped, open-cell CMC foam layer to the first CMC sheet; forming a second CMC sheet; bonding the second CMC sheet to the foam layer thereby forming a component structure; and curing the component structure.
 2. The method of claim 1, further comprising providing a plurality of flow paths through the second CMC sheet before the bonding the second CMC sheet.
 3. The method of claim 2, wherein providing the plurality of flow paths through the second CMC sheet comprises perforating the second CMC sheet.
 4. The method of claim 3, further comprising applying a thermal and environmental barrier coating to the second CMC sheet before the perforating.
 5. The method of claim 1, further comprising providing the plurality of flow paths through the first CMC sheet and the second CMC sheet by perforating the CMC sheets.
 6. The method of claim 5, further comprising staggering the perforations of the first CMC sheet and the second CMC sheet.
 7. The method of claim 5, further comprising aligning the perforations of the first CMC sheet and the second CMC sheet.
 8. The method of claim 1, further comprising: determining a component strength requirement; in response to the component strength requirement, determining at least one design parameter selected from the parameters comprising: a number of layers each layer comprising a CMC foam layer interposed between two CMC sheets, a thickness of each of the CMC sheets, a density of the CMC foam layer, and a geometric shape of the component structure; and conforming the component structure to the at least one design parameter.
 9. The method of claim 1, further comprising: determining a component cooling capability requirement; in response to the component cooling capability requirement, determining at least one design parameter selected from the parameters comprising: a sizing of the flow paths, a shape factor of the flow paths, an alignment value of the flow paths, a thermal and environmental barrier coating design, and a density of the CMC foam layer; and conforming the component structure to the at least one design parameter.
 10. A method, comprising: providing a multi-layer ceramic matrix composite (CMC) component comprising two opposing CMC sheets and a CMC open-cell foam layer therebetween; exposing one of the CMC sheets directly to high-temperature turbine engine gases; and flowing a coolant fluid through the CMC open-cell foam layer and through a plurality of flow passages defined by at least one of the CMC sheets.
 11. The method of claim 10, wherein the exposing comprises flowing turbine engine combustion gases in contact with the one of the CMC sheets.
 12. The method of claim 11, further comprising rotating the multi-layer CMC component during the exposing.
 13. The method of claim 10, wherein the flowing comprises providing a first heat transfer value from the multi-layer CMC component to the coolant fluid that is lower than a second heat transfer value, the second heat transfer value comprising a required heat transfer for a metal component.
 14. A method, comprising: forming a first ceramic matrix composite (CMC) sheet, and providing a plurality of flow paths therethrough; rigidizing the first CMC sheet into a component shape; bonding a shaped, open-cell CMC foam layer to the first CMC sheet; forming a second CMC sheet; providing a plurality of flow passages through the second CMC sheet; bonding the second CMC sheet to the foam layer after the providing a plurality of flow passages step, thereby forming a component structure; and curing the component structure.
 15. The method of claim 14, further comprising applying a thermal and environmental barrier coating to the second CMC sheet before the providing a plurality of flow passages step.
 16. The method of claim 14, further comprising providing the plurality of flow passages through the first CMC sheet prior the bonding a shaped, open-cell CMC foam layer to the first CMC sheet step.
 17. The method of claim 16, wherein the flow passages of the first CMC sheet are staggered relative to the flow passages of the second CMC sheet.
 18. The method of claim 16, wherein the flow passages of the first CMC sheet are aligned with the flow passages of the second CMC sheet.
 19. The method of claim 14, further comprising rigidizing the second CMC sheet prior to the providing a plurality of flow passages through the second CMC sheet step. 